The present invention relates generally to a decorative trim assembly for unit doors on a motor control system, and, more particularly, to bezels modularly connected to define the face layout on a unit door on a motor control system.
Trim bezels are typically used for concealing an opening between an electrical component and the panel in which it is mounted. They are usually decorative in appearance or contain indicia pertinent to the instrumentation of the system. For example, a bezel may be printed with the words xe2x80x9conxe2x80x9d and xe2x80x9coffxe2x80x9d for use around a breaker, or it may indicate the name or some other identifying mark of the system on which it is installed. Bezels are usually installed directly to the panel or fascia using tabs, clips, screws, bolts, or a combination of these methods.
The major problem with some of the prior art bezels is that they often have to be custom made for the component interface around which they are mounted. Custom made bezels are generally more expensive than mass-produced bezels and sometimes add significantly to the costs of the finished product. Even if the bezels are not custom made, prior art bezels are usually of a standard shape and design that do not allow the past offerings of a product line to be easily differentiated from the current offerings of the same product line.
Moreover, in designing the face layout and assembling an electrical panel, individual trim pieces are separately attached to the surface of the unit door. The installation of additional instrumentation also requires the installation of an additional bezel. In the prior art, adding bezels would require attaching each individual bezel using screws. Typically, these screws would be installed from the back of the instrument panel. The use of a screw as a means of attaching and securing each individual bezel, along with having to open an electrical box to install the screw from the back of the door of the electrical box, increases the costs involved with assembling the finished product.
In an exemplary embodiment of the invention, a decorative trim assembly for unit doors on a motor control center defines the individual components situated on the unit doors. Bezels are mounted to the door around components such as meters and switches. The bezels are modularly connected using bushings and receiving holes in each bezel, and are secured to the unit door with posts integrally mounted on the back sides of each bezel and retaining clips. In one alternate embodiment, mounting screws and tabs that slidably engage slots in the unit door may be used to secure each bezel to the unit door. A lip may be attached or molded into at least one edge of the bezel to allow the bezel to be easily grasped while being removed or pulled away from the unit door. The pilot device bezel may also contain a removable cutout member that allows access to a hidden door latch. The inventive decorative trim bezels may be attached to a unit door that is hingeably attached to the motor control center and contains quarter-turn latches that allow the door to be secured to the motor control center while still allowing access to the internal components of the motor control center.
The modularity of the inventive design allows for the manufacture and assembly of only a few different pieces, thus minimizing the unique part count. Furthermore, the modular assembly approach allows many different pieces to be combined to accommodate the configurations of standard height motor control units as well as the configurations of extended height motor control units.